Field of Art
The present disclosure relates generally to an image processing device, a radiography apparatus, an image processing method, and a non-transitory storage medium, and particularly to a processing technique for reducing a line artifact included in an image.
Description of the Related Art
Currently, diagnosis and treatment based on images captured using radiation such as X-rays are widely carried out. Traditionally, analog radiography apparatuses which employ films have long been used. In recent years, however, digital radiography apparatuses have come into widespread use. Digital radiography apparatuses use detectors called flat panel detectors (FPDs) in which many semiconductor elements each configured to convert radiation into an electric signal are arranged in a two-dimensional matrix. Image data obtained with an FPD is transferred to a computer and is subjected to various kinds of image processing. An image based on the image data is then displayed on a display. In this way, digital radiography apparatuses allow diagnosis to be performed.
When image processing is performed using an FPD, a line artifact (vertical or horizontal streak-like unevenness) which has a specific pattern along a certain direction of an image may appear. Because such a line artifact often has low-frequency signal components, the line artifact sometimes degrades information regarding a subject or quality of an image of a subject. As a result, the image possibly becomes an unsuitable image to be used to determine whether or not the image is a satisfactory image.
To cope with this issue, the following processing is performed. A profile indicating an amount of noise included in a non-detection area shielded from radiation is generated. Then, a line artifact is removed from an image on the basis of the amount of noise of each line indicated by the generated profile (for example, Japanese Patent Laid-Open No. 2010-22420).
However, without an appropriately obtained non-detection area shielded from radiation, profile data indicating an amount of noise in the non-detection area is not to be generated. This consequently makes it challenging to appropriately remove a line artifact from an image.